Socket receptacle for electric light bulbs



Oct. 21, 1952 c. E. GILBERT SOCKET RECEPTACLE FOR ELECTRIC LIGHT BULBS 3 Sheets-Sheet 1 Filed March 2, 1948 Oct. 21, 1952 c. E. GILBERT socxm RECEPTACLE FOR ELECTRIC LIGHT BULBS 3 Sheets-Sheet 2 Filed March 2, 1948 will,

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Oct. 21, 1952 c. E. GILBERT SOCKET RECEPTACLE FOR ELECTRIC LIGHT BULBS 5 Sheets-Sheet 3 Filed March 2, 1948 Patented Oct. 21, 1952 SOCKET EECEPTACLE FOR ELECTRIC LIGHT BULBS Charles E. Gilbert, New York, N. Y., Margaret Doris Gilbert, Norman Coates, and The Chase National Bank of the City of New York, executors of said Charles E. Gilbert, deceased Application March 2, 1948, Serial No. 12,587

12 Claims. 1

The invention relates to a new and useful improvement in the construction of socket receptacles for electric light bulbs.

One of the objects of the invention is to provide an electric light bulb socket receptacle which is provided with a pair of electrical contact blade elements which may be quickly and easily secured in place in the socket without the use of tools and in such manner that they not only make electrical contact with the bulb but will also firmly secure the ends of an electrical conductor cord to the socket and at the same time make electrical contact with the wires of said cord.

A further object of the invention is to provide a socket receptacle for electric light bulbs having slots or recesses formed therein which are adapted to receive and rigidly support a pair of electrical contact blade elements for making electrical contact with the base portion of the bulb and with the ends of an electrical conductor cord. i

A further object is to provide a socket receptacle for electric light bulbs which may be manufactured at a minimum cost and of a few parts and in which the electrical contact elements for the bulbmay be rigidly positioned therein and may be connected to an electrical conductor cord as a step in the assembly of the socket.

A further object is to provide a socket receptacle for electric light bulbs so constructed that the insulated wires of an electrical conductor cord may be securely and electrically connected with the contact elements for the bulb without removing the insulation from the wires.

A further object is to provide a socket receptacle for electric light bulbs having slots or recesses formed therein which are adapted to receive and rigidly support a pair of electrical contact blade elements for making electrical contact with the base portion of the bulb and with the ends of an electrical conductor cord and which is provided with means for locking said contact elements in said slots or recesses after they are positioned therein.

Various other objects and advantages of the invention will appear more fully hereinafter. The invention consists substantially in the construction, combination, arrangement, and relative location of parts more fully hereinafter set forth and finally pointed out in the appended claims.

In the drawings Figure 1 is a sectional view of a socket receptacle construction embodying the invention and which is adapted we used with a Christmas tree light bulb;

Figure 2 is a top plan view of the socket receptacle construction shown in Figure 1;

Figure 3 is an edge elevational view of one of a pair of removable contact blade elements which may be used in the socket construction;

Figure 4 is a front elevation of the blade element shown in Figure 3;

Figure 5 is an edge elevational view of the other removable contact blade element of the socket construction when the blade element shown in Figures 3 and 4 is used;

Figure 6 is a front elevational View of the blade element shown in Figure 5;

Figure 7 is a perspective elevational view of a modified f-orm'of contact blade element which may be used in the socket construction in place of the blade shown in Figures 3 and 4;

Figure 8 is a front elevational view of the contact blade element shown in Figure 7;

Figure 9 is a perspective elevational view of a contact blade element used in conjunction with the modified form of blade element shown in Figure 7 Figure 10 is a front elevational view of the blade element shown in Figure 9;

Figure 11 is a sectional view of a modified form of socket receptacle construction embodying the invention and showing a Christmas tree light bulb in dotted lines in position therein;

Figure 12 is a top plan view of the socket cOnstruction shown in Figure 11;

Figure 13 is a fragmentary elevational View, partly in section, showing a part of the interior construction of the modified form of socket receptacle of Figure 11;

Figure 14 is a sectional view of said socket receptacle construction parallel with the contact blade elements used therein;

Figure 15 is a front elevational view of one of the contact blade elements used in the socket receptacle shown in Figure 11;

Figure 16' is a perspective elevational view of the contact blade element shown in Figure 15;

Figure 17 is a front elevational view of the other contact blade element used in the socket receptacle shown in Figure 11;

Figure 18 is a perspective elevational view of the contact blade element shown in Figure 17;

Figure l9is a front elevational view of a modified form of a contact blade element which may be used in the socket receptacle shown in Figure Figure 20 is a perspective elevational view of the blade element shown in Figure 19;

Figure 21 is a front elevational view of a contact blade element which would be used in the socket receptacle shown in Figure 11, when the contact blade element shown in Figures 1'9 and 20 are used; and

Figure 22 is a perspective elevational view of the blade element shown in Figure 21.

In the following specification, for purpose of description, I have shown my improved socket receptacles for electric light bulbs as used for Christmas tree light bulbs. It is to be understood however that the invention is not to be limited for such use only as said receptacles are also adaptable for use generally with many other types of electric light bulbs.

Heretofore, with respect to the manufacture of socket receptacles for Christmas tree light bulbs (which are sometimes called Christmas tree light husks) it has been the practice to provide the husks or sockets with a metal cup shaped shell which is internally threaded to receive threads of the metallic base portion of the light bulb. Before this shell is mounted in the socket the end of one of the wires of an electrical conductor cord is soldered to the base of the shell and the end of the other wire of the cord is soldered to the exterior side wall of the shell. The shell is then either screwed into place inthe socket on screw threads provided on the interior face thereof and so that it is positioned to receive the threaded base portion of the bulb, or it is forced into the socket in such manner that it will have a tight fit with respect thereto. The base portion of the light bulb, when screwed orforced into the shell, will therefore make an electrical contact with th soldered wires of the conductor cord through the shell.

This form of construction of the socket for the Christmas tree light bulb has proven to be unsatisfactory for several reasons. In the first place, it is a time consuming operation to solder the ends of the conductor cord wires to the shell and then fit the shell properly in the socket so that it will properly receive the light bulb. Also, it often happens that the wires of the conductor cord are not properly soldered to the shell and they become detached therefrom so that proper electrical contact between the same and the light bulb cannot be made. Furthermore, the metallic shell used in this form of construction is comparatively expensive and, when it is screwed into place or forced into the socket, it oftentimes works loose from the same, or it becomes bent or deformed so that a light bulb cannot be properly mounted therein.

Also, in connection with the socket receptacles when used for other types of electrical light bulbs, the manufacture and assembly of the electrical contact elements for the bulbs and the assembly of the electrical conductor cord therewith has proven a costly and time consuming operation and it is the purpose of this invention to not only simplify theconstruction of the type of husk socket heretofore used for Christmas tree light bulbs, but'also to simplify and improve upon the construction of socket receptacles for electric light bulbs generally and to materially decrease the cost of manufacture of the same, and to provide a, structure which may be quickly assembled merely by inserting the bared ends of the wires of the conductor cord through the lower end of the socket and then clamping them in the socket by two contact blade elements which are adapted 4 to be positioned in the socket receptacle to not only make electrical contact with said wires but also with the base portion of the light bulb when said bulb is screwed into the socket.

Referring specifically to the drawing, the socket receptacle of the invention; as shown in Figuresl and Z, comprises a hollow body, which may be molded in a single operation from a suitable insulating material and so that it is formed with the rounded side portions I and 2, and the square shaped side portions 3 and 4. The socket rece'p'ta cle body is provided with the usual opening Eat the top thereof through which the Christmas tree light bulb'is received, and with the opening 6 through the base portion thereof through which the wires I and 8 of an electrical conductor cord are adapted to be inserted. The interior faces of the rounded side portions I and 2 are provided with the screw threads 9 and II) which are adapted to receive the threads formed on the exterior surface of the metallic base portion of the light bulb. The interior faces of the square shaped sides 3 and 40f the socket construction are formed with the grooves or' recesses II and I 2 which extend the length of the socket and terminate with a closed end at the base thereof. These grooves or recesses are adapted to receive therein the electrical contact blade elements I3 and I4,-or I5 and I6, which will be described more in detail later on herein. The grooves or recessesII and I2 are made slightly wider than the width of thecontact blade elements which are intended to be positioned therein and so that-said contact blade elements will have a snug sliding fit. The said grooves or recesses are separated at their lower ends from the-central base opening 6 of the socket construction by the upwardly extending ribs IT and I8.

The contact blade elements I3 and I4, shown in Figures 3-, 4, 5 and 6, are made by a single stamping operation from a; strip of suitable elec' trical conducting material. The contact element I3 is so stamped from said conducting material that it is provided with a long'leg portion I9 of a Width adapted to have a close sliding fit in the groove II of the socket, and. with a short leg 20 less in width than leg I9, and which is bent at 2| with respect to leg I9 and so that it extends outwardly and downwardly from said leg. The lower endof leg I9 is provided with a V-shaped cut out portion 22 therein, the purpose of which will be later referred to. The contact blade element I4, shown in Figures 5 and 6, is stamped from electrical conducting material and bent with a U-shaped bend 23', so that it is provided with a vertically extending leg portion 24 which is adapted to have a close sliding fit in groove I2 of the socket, and with a horizontally extending leg portion'25 Which is adapted to extend across the central wire receiving opening 6, at the base of the socket, when said contact blade element I 4 is positioned in its groove I2 of the socket. The bent U-shaped portion 23 is provided with a V-shaped cutout portion 26, the purpose of which will be more fully referred to hereinafter.

To assemble the contact blade elements in the socket receptacle and to connect said blade elements to an electrical conductor cord the two insulated wires "I and 8 of said cord are first separated from each other and the insulation removed from the ends thereof. Then the two bared ends of the cord are inserted into the socket through the base opening 6 until the said bared ends project into the socket body and across the upwardly extending ribs I! and I8 thereof. The

long leg ll! of the contact blade element It is then inserted into the groove or recess H formed in the socket and forced downwardly in the groove or recess with the V-shaped cutout opening 22 thereof at its lower end pressing against the bared end of the conductor wire 1 and until said blade element is positioned in the bottom portion of said groove and so that it will pinch said wire between the sides of the groove I! and the rib fl. When the blade element 13 is fully positioned in its groove H the insulated portion of the wire will be folded over the rib IT and the wire will assume the position shown in Figure 1. Then the leg 24 of the contact blade element M is forced into the groove or recess l2 of the socket with the V-shaped cutout portion 26 thereof, which is formed in the U-shaped bent portion 23, pressing the bared wire end of the other conductor cord 8 downwardly into the bottom of said groove or recess and until the said wire is folded around the bent U-shaped bent portion 23 and it will assume the position shown in Figure 1, with the bared end of said wire pinched between the side wall of the socket and the rib l8, and with the,

insulated portion thereof bent sharply overthe top edge of said rib. When the wires of the conduotor cord are thus positioned in the socket, secure contact is made between the contact blade elements and the conductor cord and if the cord should be pulled the strain will be largely absorbed by the insulated portion of the cord which is bent over the ribs H and I8 and removed from the non-insulated ends thereof and the permanency of the attachment of the cord to the contact elements will be positively assured.

/ When the contact blade element i3 is fully seated in the groove ll of the socket, the bent leg portion 2B thereof will extend resiliently outwardly from the leg 19. When the leg 24 of the contact blade element It is fully seated in the groove [2 of the socket construction, the horizontally extending leg portion 25 thereof will project inwardly of the socket and horizontally across the lower end thereof as clearly indicated in Figures 1 and 2.

When an electric light bulb such as a Christmas tree light bulbis inserted into the assembled socket construction above described, its screw threaded metallic base is screwed into place therein by means of the screw threads El and ill formed on the interior faces of the curved sides I and 2 of the socket, and when the bulb is fully positioned in the socket, the base face thereof will be in electrical contact with the horizontally extending leg portion 25 of the contact blade element It and thus establish electrical contact with the wire 8 of the conductor cord. Also, the side of the base of the bulb will be pressed against the resilient inwardly extending leg portion it of the contact blade element is and thus electrical contact of the bulb with the wire '5 of the conductor cord will be positively established.

' With respect to the contact blade elements of the type shown in Figures 7, 8, 9 and 10 and which may also be used in the socket receptacle construction of the present invention, the contact blade element 15, shown in Figures 7 and 8, is stamped from one piece of conducting material in such manner that it is formed with the main leg portion 21 which is adapted to have a snug sliding fit in the groove or slot ll of the socket and is provided at its lower end with a cutout portion 28 in which is formed a pointed V-shaped member 29. Stamped out of the leg portion 21 is a tongue 30 which is bent so that it will extend outwardly from the leg portion 21 and in a downwardly curved direction.

The contact blade element 16, shown in Figures 9 and 10, is stamped from a piece of conducting material in such manner that it is provided with a main leg portion 3|, which is adapted to have a snug sliding fit in the groove or slot I2 of the socket and it is also provided at its lower end with a cutout portion 32 in which is formed a pointed V-shaped member Stamped out of the leg portion 3| of this contact blade element is a tongue 34 which is bent outwardly and so that it extends in a horizontal direction to the plane of the leg portion 3i.

The contact blade elements shown in Figures '2, 8, 9 and 10 are designed for connection to the wires of a conductor cord for the socket receptacle without removing the insulation therefrom. For this reason the pointed V- shaped members 29 and 33 are provided in the cutout portions 28 and 32 at the lower ends of the legs 2'! and SI of the contact blade elements which insures that when said contact blades are fully inserted completely into the slotted recesses H and I2 of the sockets, and against the insulated ends of the conductor cord,,the V- shaped pointed members 29 and 33 will pierce the insulation of the cords and establish electrical contact with the wires of said cord. The cutout portions 28 and 32 at the lower ends of the legs 2'! and 3! of these contact blade elements also function to clamp the cords securely over the ribs ll and iii of the socket so that said conductor cord will be held securely against displacement with respect to the socket.

In assembling the contact blade elements shown in Figures 7, 8, 9 and 10, and the electrical conductor cord, with the socket receptacle, the same procedure is followed as above described in connection with the assembly of the blades It and I l with the cord and socket. The contact blade element I5 is forced downwardly in the groove or slot H' with its lower cutout portion 23 gripping the end of the insulated cord 1 and with said end clamped over the rib [6 of the socket construction, and also with the V-shaped pointed member 33 thereof, piercing through the insulation of the cord. The contact blade element It is likewise forced downwardly in the groove or slot I2 of the husk socket with its lower cutout portion 32 gripping the insulated cord 8 in the bottom of the groove and with the end of the cord clamped over the rib l3, and also with the V-shaped pointed member 33 of the contact element piercing through the insulation of said cord. When the contact blade element i5 is in position with respect to the husk socket the prong 30 thereof will extend inwardly into the socket body and so that it will make a resilient electrical contact with the side of the base of the electric light bulb, and the contact blade element It, whenfully inserted in the groove or slot i2 of the socket receptacle, will have the tongue 34 thereof positioned so that it will provide an electrical contact with the bottom face of the base of the electric light bulb.

In Figures 11 to 22 inclusive there is shown a modified form of construction of socket receptacle for electric light bulbs within the scope of my invention.

In this modified form of construction the socket construction, as shown in Figures 11, 12 and 14,

oomprisesa hollow body 35 molded or a suitablev insulatingmaterial and-provided withthe rounded sidev portions 36 and 31, and the square shaped side portions38and 39. The socket receptacle body is provided with a top opening 40 through which the base of an electric light bulb is adapted to begreceived, and with the opening 4| through the. base portion thereof through which the electrical conductor cords 42 and 43 are inserted. The interior faces of the rounded side portions 36 and.3l in this. particular form of construction are not provided with screw threads, such as are provided in thesocket receptacle shown in Figures 1 and2, but are smooth. The interior faces of the square shaped side portions 38 and 39 are formed with the ribs 48, 49, 50 and which are positioned in spaced relation to the ribs 44, 45, 46 and 41. formed on the interior wall of the receptacle, so, as to form grooves or recesses in which the electrical contact blade elements 58 and 60 are to be described more fully hereinafter. The ribs 48, 49, 59 and 51 are formed with the downwardly sloping faces 52, 53, 54 and 55 and each of said ribs is provided with a projecting portion 56, as indicated more clearly in Figure 13, which terminatesin a lower edge such as is indicated at 51 in Figure 13. The grooves or recesses formed by the ribs 44, 45, 46 and 41 and the ribs 48, 49, 59 and Stars slightly wider than the width of the electrical contact blade elements 58 and 69, and so that said bladeelements will have a snug sliding fit therein. The ribs 44, 45, 46 and 41 are joined at their lower ends by the V-cut upwardly extending projections 59 and 6!, as more clearly shown in Figure 14.

The contact blade, elements 58 and 69, used in this form of socket receptacle construction, are shown in Figures 14, 15, 16 and 17. The contact blade element 58 is stamped from a strip of electrical conducting material and shaped so that it is provided with a leg portion 62 which is formed so that it'is provided with an upper bent portion 63 and a lower reduced portion 64 formed with a V-shaped cutout portion 55. Stamped out of the leg portion 62 is a tongue 66 which has its free end 61 bent upwardly and outwardly from the leg portion 62.

The other contact blade element 69 used in this form of socket receptacle, and shown in Fig ures l7 and 18, is stamped from a piece of electrical conducting material and bent so that it is provided with a vertically extending portion 68 having-a bent upper edge portion 59, and a horizontally extending portion 15 which is provided with cutout portions H and 72. The horizontally extending'portion has a tongue 13 stamped therefrom which is bent downwardly, and. so that it extends in line with the vertically extending portion 68 of the contact element. The tongue 13 is formed at its free edge with the V-shaped cut-out portion I4.

In assembling the contact blade elements 58 and 56, and the electrical conductor cords 42 and 43, with the socket receptacle 35, and in connecting the said contact blade elements to the electrical conductor cords, the ends of the two cords are separated from each other and the insulation removed therefrom. Then the two bared ends of the cords are inserted into the socket receptacle through the base opening 4! thereof until the said bared ends project into the socket receptacle and across the V-cut projections 59 andiil. The leg 62 of the contact blade element 58 is then inserted in the groove formed by the ribs 46, 50,

4'! and 55, and is forced downwardly in said groove until the V-cut 65 thereof at its lower end presses the bared end of the conductor cord 43 into the bottom of the groove. When the contact blade element 58 is fully seated in its groove in the receptacle, the upper curved end 63 thereof will snap under and engage under the bottom edges 5? of the projections 55 of the ribs 50 and 5|, thus locking the contact blade element in place with respect to the socket receptacle and with its resilient tongue 66 projecting inwardly of the receptacle. Also, when the contact blade element 58 is fully seated in its groove in the receptacle socket, the insulated portion of the conductor cord 43 Will be firmly wedged in the V- shaped cutout portion of the projection 65 of the receptacle socket. Then the contact blade element 63 is inserted in its groove formed by the ribs 44, 45, 52 and 53, and until the V-shaped cut away portion of the downwardly extending tongue 73 thereof grips the bared end of the conductor cord 42 in the bottom of the groove and with the insulated portion of the cord wedged into the V-haped cutout portion of the projection 59 of the socket receptacle. When the contact blade element 58 is fully seated in its groove. the upper bent portion 69 thereof will snap under the lower edges 5'! of the projections 56 of the ribs 52 and 53 as shown particularly in Figure 13, and it is securely locked in position in the socket re ceptacle and with the leg portion '19 of the contact blade element extending horizontally inwardly and across the lower end of the receptacle socket as clearly shown in Figure 11.

When an electric lightbulb is to be inserted into the assembled modified form of socket receptacle the bottom metallic screw threaded portion I5 of the bulb is inserted down into the receptacle through the upper opening 40 thereof and until the bottom of the metallic screw threaded portion is in electrical contact with the horizontally extending portion 10 of the contact blade element 69. This electrical contact is made with the electrical conductor cord 42. Also, when the metallic screw threaded portion of the bulb is seated within the socket receptacle the curved end portion 61 of the resilient outwardly extending tongue 66 of the contact blade element 58 will engage in one of the screw threads 01 the. screw threaded portion of the bulb and not only hold the bulb in position in the socket receptacle but also causes an electrical contact to be made with the conductor cord 43.

InFigures 19, 20, 21 and 22 are shown modified forms of contact blade elements which may also be used in the socket receptacle shown in Figure 11. In Figures 19 and 20 the contact blade element 16 is stamped out of a strip of electrical conducting material and is shaped so that it is provided with a leg portion 11 which is formed with an upper bent portion 18 and a cut away reduced portion at 19. The reduced portion is bent at 83 into a U-shape and so that there is provided a vertically extending portion 8|, which in turn is bent to form the horizontally extending portion 82. The other contact blade element 83, which is used in conjunction with the blade element l6 and shown in Figures 21 and 22, is stamped from a piece of electrical conducting material and is bent so that it is provided with a vertically extending portion 84 having a bent upper end 85. The bent upper end is cut away to form a reduced portion 86 which is bent at 8! to form a curved upper leg portion 88 which extends outwardly at its central portion and with its lower end 89 curved outwardly towards leg 84.

The contact blade elements shown in Figures 19 to 22 are assembled in the socket receptacle and in conjunction with the electrical conductor cord in the same manner as described in connection with the blade elements shown in Figures to 18. When the contact blade elements 16 and 83 are in place in the socket receptacle, the bottom of the metallic screw threaded portion of the bulb, when said bulb is inserted into the receptacle, will be in electrical contact with the horizontally extending portion 82 of the contact blade element 16 and the outwardly bent tongue 88 of contact blade element 83 will engage between one of the screw threads of the screw threaded portion of the bulb base and thus cause electrical contact to be made with the con ductor cord 43.

From the foregoing it will be seen that I have provided an exceedingly simple and eflicient construction for socket receptacles for Christmas tree light bulbs or other electric light bulbs which are made of a few simple parts which are cheap to manufacture and also the parts of the socket receptacle may be quickly and readily assembled with little labor, and without the use of tools. Also when the parts are in assembled relation there is provided; a ruggedly constructed socket receptacle which will not get out of order and which will not only provide such electrical contact with the base of an electrical light bulb but which also will withstand unusual strains that may be placed upon the conductor cord connected thereto.

What is claimed is:

1. An electrical socket receptacle for electric light bulbs consisting of a hollow body made of an insulating material and formed with rounded side walls and fiat shaped end walls and having a pair of grooved recesses formed on the interior faces of said fiat shaped end walls, said grooved recesses having a, width greater than the smallest separation of said rounded side walls, and screw threads formed on the interior faces of said rounded side walls, electrical contact elements slidably seated in said recesses with a pressed fit, said contact elements having a groove engaging portion wider than said smallest separation of said rounded side walls and being provided with means at their lower ends to grip and hold the bare wire ends of an electrical conductor cord in said recesses and to make electrical contact therewith and also with means for making electrical contact with the base portion of an electriclight bulb when said bulb is screwed into said socket on'said screw threads, said contactmaking means comprising respective portions of said contact elements of a width less than said smallest said separation of said rounded side walls and projecting into the cylindrical space defined by said rounded side walls.

2. An electrical socket receptacle construction adapted to have an electric light bulb mounted therein, comprising a hollow body made of an insulating material and having an opening through its base and having rounded side walls and flat shaped end walls and a pair of vertically extending grooved recesses formed on the interior face of said flat shaped end walls, said body having opposed projections extending parallel to and spaced from'the interior faces of said flat side walls, whereby each of said grooved recesses is partially enclosed, an electrical conductor cord having its ends inserted through said base open ing of the socket body, electrical contact elements slidably seated in said grooved recesses with a pressed fit and making electrical contact with the ends of said conductor cord and gripping and clamping the wires of said cord and also being provided with outwardly extending tongues of a width less than the separation between opposed ones of said projections for making electrical contact with the base portion of an electric light bulb when said bulb is inserted in said socket.

3. An electrical socket receptacle construction as in claim 2 wherein the inner surfaces of said hollow body side walls are formed with threads for receiving the threaded base portion of an electric light bulb when said bulb is inserted in said socket.

'4. An electrical socket receptacle construction as in claim 2 wherein the inner surfaces of said rounded side walls of said hollow body are smooth, one of the outwardly extending tongues of said electrical contact elements being bent outwardly from the plane of its respective grooved recess at an acute angle for retaining the base portion of an electric light bulb seated within said hollow body upon insertion of said bulb into said socket.

5. An electrical socket receptacle construction as in claim 2 wherein each of said electrical contact elements is formed at its end seated within its grooved recess with a pointed projection adapted to pierce the insulation of unbared wires of said conductor cord upon sliding insertion of said electrical contact elements into their respective grooved recesses with said conductor cord wires in place.

6. An electrical socket receptacle construction as in claim 2 wherein each of said electrical contact elements is formed at its end, seated in the base of its respective grooved recess with a notch adapted to make electrical contact with the bared end of a respective wire of said conductor cord upon insertion of said electrical contact elements in their respective grooved recesses with said wires in place.

7. An electrical socket receptacle construction as in claim 2 wherein said hollow body is provided with a projecting shoulder adjacent the bulbinserting end thereof at the end of each of said grooved recesses, said electrical contact elements being formed with a bent outer end which, upon insertion of said contact elements in their respective grooved recesses, engages under a respective one of said shoulders to prevent withdrawal of said electrical contact elements.

8. An electrical socket receptacle construction for electric light bulbs comprising a body made of an insulating material and formed with rounded sidewalls and flat shaped end walls and having an opening in the base thereof for the reception of an insulated electrical conductor cord, and a pair of grooved recesses closed at one end formed on the interior faces of said fiat shaped end walls, said grooved recesses having a width greaterthan the smallest separation of said rounded side walls whereby said recesses are partially enclosed, an electrical conductor cord inserted through the base opening of the socket receptacle and having the ends of the wires there'- of positioned in the grooved recesses, electrical contact elements seated in said grooved recesses with a pressed fit, said contact elements consisting of metallic strips of conducting material provided with cutout portions at the lower ends thereof for making electrical contact with the wires of said conductor cord and for clamping'said wires in said grooved recesses, and also provided with outwardly extending tongues nar- "rowerthan said-smallest side wall separation for 'making electrical contact with the metallic base portionof an electric light bulb when said bulb is mounted in said socket.

'9. An electrical socket receptacle for electric light'bulbs consisting of a hollow body made of insulating material and formed with rounded side walls and flat shaped end walls and having a pair of'grooved recesses formed on the interior face of said fiat shaped end walls, said grooved recesses having awidth greater than the smallest-separation of said rounded side walls, whereby'said recesses are partially enclosed, a pair of electrical contact elements seated in said grooved smallest separation adapted to make electrical contact with the side of the base portion of the light bulb, and the other of said contact elements consisting-of a'strip of conducting material bent in such-manner that there is provided a vertically extending" leg portion adapted to be seated in the other of'said grooved recesses with pressed fit and a horizontally'extending leg portion narrower than'said smallest separation and adapted to make electrical contact with the bottom face of the light bulb.

10. A'n electrical socket receptacle for electric light bulbs consisting of a hollow body made of insulating material and formed with rounded side walls and flat shaped end walls and having a :pair ofgrooved recesses formed on the interior face of said fiat shaped end walls, said smallest separation of said rounded side walls,

whereby said'recesses are partially enclosed, a :pair of removable electrical contact elements seated in said grooved recesses with a pressed fit and adapted to make electrical contact with the base of theli'ght bulb and with an electrical conducting-cord inserted in said socket receptacle, one'of sai'd contact elements consisting of a strip of conducting material adapted to be seated in one of the grooved recesses with a pressed fit and having an-outwardly extending resilient prong vi of a width narrower than said smallest separationand adapted to make electrical contact with "the side of the base portion of the light bulb, and

the other of said contact elements consisting of a .stri rof conducting material adapted to be seated inithe'other grooved recess with a pressed fit and .having a resilient prong of a width narrower than said smallest separation and which is bent so toexten'd horizontally from the plane of said contact element and so'that it will be positioned :to make electricalcontact with the bottom termi- "nal ofthe. light bulb.

'11. An electricalsocket receptacle for electric light bulbs consisting of a hollow body made of insulating material and formed with rounded sidewalls and flat shaped end walls and having .an .openlng'through the base thereof and a pair i-grooved'recesses having'a width greater than the Number 12 of vertically extending grooved recesses'formed on the interior face of said flat shaped endwalls and closed at their lower ends, said grooved recesses having a width greater than the smallest separation of said rounded side walls, whereby said recesses are partially enclosed, an electrical conductor cord having its ends inserted through said base opening of the socket body, contact elements slidably seated in said grooved recesses with a pressed fit and making electrical contact with the ends of said conductor cord and also being provided with means for making electrical contact with the base portion of an electric light bulb when said bulb is inserted in said socket, said contact-making means comprising respective portions of said contact elements'of a width less than said smallest separation of said rounded side walls and projecting into the cylindrical space defined by said rounded side walls, and ribs formed in said socket at the base thereof and adjacent the base of said recesses and over which greater than the smallest separation 'of said rounded side walls, said rounded-side walls having screw threads formed on theinteriorfaces thereof adapted to engage the screw threads of a lampbase, an electrical conductor cord having its ends inserted through said bottom opening, a pair of electrical contact blade members, each formed with a vertically extending long leg portion and with a short leg portion of a width narrower than said smallest separation and which is bent so that it extends outwardly of said grooved recesses with respect to said long leg, said vertically extending long leg portion of said contact blade members being slidably seated in said grooved recesses ina pressed fit with its .lower end clamping the ends of the wires of said electrical conductor cord in said grooved recesses and making electrical contact with said wires .and said short legs extending inwardly of said socket'receptacle from said grooved recesses and adapted to make electrical contact with the base of an electric light lamp.

CHARLES E. GILBERT.

REFERENCES CITED The following references are of record in the file of this patent:

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